SHORT FUSE: Mets manager Terry Collins gets tossed by umpire Doug Eddings just two batters into last night’s 9-1 win over the Astros at Citi Field.Getty Images

This was a great night for the Mets. Jason Bay finally returned to the lineup, and nearly everyone’s trade value went up as the Mets belted the Astros around Bag Citi. To top it off, the club got $25,000 back from the Blue Jays, who agreed to take back second baseman Brad Emaus.

This was a night Mike Nickeas hit his first major league home run, David Wright regained his major league stroke, lashing a home run and a double, and Ike Davis blasted an impressing drive to the right of The Apple in the 9-1 win.

Wright, who is trying to get a few laughs in the clubhouse after home wins by wearing a muscle T-shirt with huge photos of himself, noted, “Anytime you hit a home run in this place, it’s got to take a pretty good swing.”

But this was a day general manager Sandy Alderson, who said he was not aware that some fans had been wearing paper bags on their heads at Citi Field this week, made it clear the minor league cupboard is bare at the highest levels.

That only can mean one thing: There will be a serious restocking of the shelves.

You can sense the day is coming when Alderson backs up the truck and trade whoever he can, starting with Jose Reyes and probably Wright, too. Davis might be young enough to keep around, but there really are no untouchables.

This, though, is not the time to trade as Alderson pointed out. No, this is time to build trade value.

“In terms of trades, clubs aren’t doing anything now, they’re all assessing their own situations,” Alderson said before the game.

There’s no immediate help on the farm, and that is telling in many ways.

“We just don’t see that there are a lot of options for us right now in the minor leagues,” Alderson said. “We just don’t have the kind of depth at the upper level of the minor league system that you’d like to have. Options are limited.

“Probably the best thing I can do right now is stay out of the way.”

For a little while at least, then it’s time to get to work and restock the minor leagues and build for the future.

Regarding the fans who showed up this week wearing bags over their heads, the optimistic Alderson said, “As I recall it, that phenomenon originated in New Orleans and not too long ago they won the Super Bowl, so things do change.”

Of course, it took the Saints a couple of generations to win that Super Bowl.

The Mets hope it won’t take Alderson that long to turn things around. Nevertheless, he made it clear the cavalry is not coming over the hill.

Alderson said the dreadful home start (now 2-8) has created a “nightly crucible” for the fans, but added that it’s hard on the organization, too.

“Everyone of us goes through it,” he said. “Every player goes through it, every staff member. I’ve seen one win in this ballpark.”

Now he’s seen two.

“You do have to keep an eye on the long term, but within a six- or seven-day time frame, it’s all consuming,” Alderson said. “There’s not a lot someone in my situation can do. It’s almost organic at that point. If it’ll happen, it will happen from within.”

Asked if he had a helpless feeling, Alderson said, “I think you do have to recognize when you have options and when you don’t really have options. I don’t even want to suggest if we had options that we’d do something at this point.”

This week is the Battle for the 2012 top draft pick against the Astros and now the Diamondbacks, another way for Alderson to build. And if that’s the case, last night hurt the cause.

Manager Terry Collins did his part to get the Mets going by getting thrown out arguing a strikeout that wasn’t called — to the second batter of the game.

This is all about accountability for the Mets, from Alderson on down. It won’t be long before the big deals will come down, and Alderson will have to be at the top of his game.